Unable to find a @SpringBootConfiguration when doing a JpaTest

java

spring-boot

jpa

testing

byNikita Barsukov·Oct 6, 2024

To ensure your test can locate the Spring Boot configuration, you should either position your test class properly in the package hierarchy or explicitly direct it to your main application class.

For JPA component tests, use @DataJpaTest combined with @AutoConfigureTestDatabase to adjust the database settings:

@DataJpaTest
@AutoConfigureTestDatabase
public class YourRepositoryTests {
    // Repository tests go here, no party crashers allowed!
}

Alternatively, for a wider testing scope requiring the whole Spring context, use @SpringBootTest:

@SpringBootTest
public class YourRepositoryIntegrationTests {
    // Comprehensive integration tests, making sure no stone is left unturned!
}

Keep your test configuration visible by maintaining the test classes in the same package or sub-package as your main application class. Alternatively, use @ContextConfiguration to explicitly define it:

@DataJpaTest
@ContextConfiguration(classes = YourApplication.class)
public class YourRepositoryTests {
    // Focused JPA tests, let's jump right into the pool!
}

Utilize Spring Boot's testing support for both comprehensive and slice tests, covering application context and database interactions.

Nailing the packages and the main entry point

Your main application class should use @SpringBootApplication for auto-configuration. This annotation simplifies the setup of configuration classes, including @Entity classes and JPA repositories:

@SpringBootApplication
public class YourApplication {
    public static void main(String[] args) {
        SpringApplication.run(YourApplication.class, args);
    }
}

Ensure your test classes rest in the same package, or a sub-package of your main application class. Aligning the packages helps Spring Boot to figure out your test configuration without needing additional clues:

com.yourapp
├── YourApplication.java // annotated with @SpringBootApplication
└── repository
    └── YourRepositoryTests.java // your JPA test class

Opting for the most suitable testing scope

Decide whether you need a part of the context (perfect for focused testing) or the whole Spring application context (for broader tests):

The @DataJpaTest is excellent for focused JPA testing. It loads only a part of the context, ensuring you remain focused on your database interactions!
Use @SpringBootTest when comprehensive integration tests are required. If you want to set the entry point to a different configuration class, use @SpringBootTest(classes = MyAlternateConfig.class).

If you're not dealing with testing related to the Web layer, avoid using @SpringBootTest(webEnvironment = ...). Hints like these ensure that your tests load swiftly by avoiding unnecessary configuration.

Configuration specifics for multiple branches

If you need multiple configurations due to requirements like branching, @ContextConfiguration comes handy. This annotation tells the test context exactly which classes or locations to consider:

@Configuration
public class TestConfig {
    // Test specific beans and configurations
}

And apply it in your test class:

@RunWith(SpringRunner.class)
@DataJpaTest
@ContextConfiguration(classes = TestConfig.class)
public class YourRepositoryTests {
    // JPA tests that love to party with specific TestConfig
}

Renaming or refactoring your packages? Realign your test class’s package declaration to match the new structure.

Clean code, cleaner application

A lean main application class without extraneous annotations or code snippets avoids potential issues and confusions. Unless explicitly needed, refrain from using @ComponentScan, @EntityScan, or @EnableJpaRepositories - why invite confusion when you don’t need to?

Add @RunWith(SpringRunner.class) with your @DataJpaTest to leverage Spring's testing support in JUnit 4. For JUnit 5, you would use @ExtendWith(SpringExtension.class):

@DataJpaTest
@ExtendWith(SpringExtension.class)
public class YourRepositoryJUnit5Tests {
    // Behold! JUnit 5 repository tests coming your way!
}

Playing detective with common issues

Missing dependency: Ensure spring-boot-starter-test is listed as a dependency in your pom.xml or build.gradle file.
Misplaced classes: Ensure no class with @SpringBootConfiguration annotation is lost outside Spring Boot's scanning scope.
Duplicate configurations: Having multiple @SpringBootApplication or @SpringBootConfiguration annotated classes can confuse Spring's auto-detection. Avoid duplication!